Molecular Vibration: a Certain Diatomic Molecule Emits a Photon of Energy

Multiple Choice

Molecular vibration: A certain diatomic molecule emits a photon of energy 1.20 eV when it makes a transition from the n = 1 vibrational state to the next lower vibrational state. If the molecule made a transition from the n = 2 state to the n = 1 state, what would be the energy of the photon it would emit? (h = 6.626 × 10^-34 J ∙ s, ħ = 1.055 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J)

A) 3.60 eV
B) 2.40 eV
C) 1.20 eV
D) 0.60 eV
E) 0.30 eV